Correlates of Fatigue in Patients with Neuromyelitis Optica

Objective To determine clinical characteristics associated with fatigue in patients with neuromyelitis optica (NMO). Methods A questionnaire survey was conducted in NMO patients, measuring fatigue using the fatigue impact scale (FIS). Results A total of 64 NMO patients (mean age: 50.0 years; male/female: 3/61) completed the survey: 71.9% were NMO-IgG seropositive and 43 (67.2%) received immunosuppressive treatments. The patients obtained a global FIS score of 64.8±36.1, with 13.2±8.5, 20.6±11.6 and 31.0±18.7 for the cognitive, physical and social dimensions, respectively. No significant differences were found in global FIS scores （ P=0.294 9）, and cognitive （ P=0.467 1）, physical （ P=0.472 2） and social （ P=0.212 6） dimensional scores between those with and without immunosuppressive treatments. Age, sex, serum NMO-IgG, duration of disease and annual relapse rates were neither correlated with global FIS scores （ P>0.05）, nor with the three dimensional scores （ P>0.05). The Expanded Disability Status Scale score was positively associated with global FIS scores （ P=0.000 5）and cognitive（ P=0.018 7）, physical（ P=0.000 4） and social （ P=0.000 5）dimensional scores. The frequency of attack was also positively correlated with cognitive dimensional scores （ P=0.007 9）.Conclusion Disability is associated with cognitive, physical and social dimensions of fatigue. High frequency of attack is positively correlated with the cognitive dimension of fatigues.